Hi, all.
Trying to add a local user to a CentOS 6.3 system that is using ldap for
Samba authentication, but being stymied by the user's existing entry in
ldap.
|[root@samba ~]# adduser wchandy
adduser: user 'wchandy' already exists
[root@samba ~]# useradd wchandy
useradd: user 'wchandy' already exists
|
User is not already a local user:
|[root@edgar2 ~]# grep wchandy /etc/passwd
|
But they are a Samba user in ldap:
|[root@edgar2 ~]# smbldap-usershow wchandy | grep uid
dn: uid=wchandy,ou=people,dc=ucsc,dc=edu
uid: wchandy
uidNumber: 30490
|
adduser does not have a local option. How does one get adduser to add
local users in the presence of ldap authentication.
Other things to consider:
* There are currently local users who share a uid with an ldap entry
(with a different uidNumber) who can access samba and ssh
independently. I want to be able to keep doing this, AND add more
users like this when needed.
* No, I don't want to edit the user directly into /etc/passwd and
/etc/group. I'd like to fix the underlying problem. Plus now any new
local entry interferes with the same user's access to samba.
* No, I don't want to rely on ldap for local ssh login.
* No, I don't want to use a different uid for the user.
I originally set up my samba-ldap authentication with the handy (but
seemly irreversible) authconfig command:
|[root@samba ~]# authconfig --enableshadow --enablemd5 --enableldap \
--enableldapauth --enableldaptls --enablemkhomedir \
--ldapserver=dir.mydomain.com --ldapbasedn="dc=mydomain,dc=com" \
--enablelocauthorize --updateall
|
My /etc/sysconfig/authconfig looks like this:
|IPADOMAINJOINED=no
USEMKHOMEDIR=yes
USEPAMACCESS=no
CACHECREDENTIALS=yes
USESSSDAUTH=no
USESHADOW=yes
USEWINBIND=no
PASSWDALGORITHM=sha512
FORCELEGACY=no
USEFPRINTD=yes
USEHESIOD=no
FORCESMARTCARD=no
USEDB=no
USELDAPAUTH=yes
IPAV2NONTP=no
USELDAP=yes
USECRACKLIB=yes
USEIPAV2=no
USEWINBINDAUTH=no
USESMARTCARD=no
USELOCAUTHORIZE=yes
USENIS=no
USEKERBEROS=no
USESYSNETAUTH=no
USESSSD=no
USEPASSWDQC=no
|
My samba config was migrated from an RHEL4.x system to CentOS 6.3. Now
instead of the kludgy mashup of nss and pam and who knows what, I used
the pretty slick and easy sssd.
My /etc/sssd/sssd.conf looks like this:
|[domain/default]
cache_credentials = True
#cache_credentials = False
ldap_search_base = dc=mydomain,dc=com
krb5_realm =
EXAMPLE.COM
krb5_server =
kerberos.example.com
id_provider = ldap
auth_provider = ldap
chpass_provider = ldap
ldap_uri =
ldap://dir.mydomain.com/
ldap_tls_cacertdir = /etc/openldap/cacerts
#ldap_tls_reqcert = allow
entry_cache_timeout = 5
debug_level = 31
[sssd]
config_file_version = 2
services = nss, pam
# SSSD will not start if you do not configure any domains.
# Add new domain configurations as [domain/<NAME>] sections, and
# then add the list of domains (in the order you want them to be
# queried) to the "domains" attribute below and uncomment it.
# domains = LDAP
domains = default
#debug_level = 31
[nss]
[pam]
debug_level = 31
|
As a workaround I came up with two non-optimal solutions. It at least
gave me a way of moving forward after I found myself in the sticky
situation where LDAP and the local passwd file are blocking each other.
Workaround 1: I created a local user with a different UID (username) to
give ssh access to a person who already had an LDAP/Samba entry.
Possibly the cheeziest sysadmin solution I've done in years.
Workaround 2: A little more complicated but comes down to adding the
local user with the same uidNumber as in LDAP.
1. Lookup LDAP uidNumber with getent, ldapsearch, or smbldap-usershow
2. Temporarily disable the user in LDAP in order to add the local user
without conflicts
3. Create the local account matching the uidNumber with LDAP
4. Re-enable the user in LDAP
Both of these work, but neither address the underlying issue of allowing
the authentication to use LDAP exclusively for Samba auth and
/etc/passwd for local auth. But in the absence of another solution, this
will have to do.
Thanks for the help. If I can get my local and samba-ldap authentication
working independently I'll be stoked.
Wes
--
------------------------------------------------------------------------
Wes Modes
Systems Designer, Developer, and Administrator
University Library ITS
University of California, Santa Cruz